Elastic laminate including nonwoven layer formed from highly-oriented-component fibers and disposable garment employing the same

ABSTRACT

The present invention is directed to an elastic laminate which is elastically extensible in at least one direction. The elastic laminate includes an elastomeric material having a first surface and a second surface opposing the first surface; and a first nonwoven layer joined to the first surface of the elastomeric material. The first nonwoven layer is formed from component fibers having a primary fiber direction. The first nonwoven layer has a Fiber Orientation Ratio within about ±20 degrees from a primary fiber direction of at least about 65%. The present invention is also directed to a disposable garment employing such an elastic laminate.

FIELD

The present invention relates to elastic laminates. More specifically,the present invention relates to elastic laminates which includes anonwoven layer formed from highly oriented component fibers. The presentinvention also relates to disposable garments employing such elasticlaminates. Examples of such disposable garments include disposableunderwear, disposable diapers including pull-on diapers and trainingpants, and disposable panties for menstrual use.

BACKGROUND

Elastic laminates have previously been used in a variety of disposableproducts, including sweat bands, bandages, body wraps, and disposablegarments including disposable diapers and incontinence devices. Herein,“elastic laminate” refers to an elastically stretchable two or morelayered materials including at least one elastically stretchable singlelayer material. It is generally expected that these products providegood fit to the body and/or skin of the user by using suitable elasticmembers during the entire use period of products.

A “zero strain” stretch laminate is one type of elastic laminate whichis preferably used for such disposable products. For example, methodsfor making “zero strain” stretch laminate webs are disclosed in U.S.Pat. No. 5,167,897 issued to Weber et al. on Dec. 1, 1992; U.S. Pat. No.5,156,793 issued to Buell et al. on Oct. 20, 1990; and U.S. Pat. No.5,143,679 issued to Weber et al. on Sep. 1, 1992. In a manufacturingprocess for such “zero strain” stretch laminate, the elastomericmaterial is operatively joined to at least one component material in asubstantially untensioned (zero strain) condition. At least a portion ofthe resultant composite stretch laminate is then subjected to mechanicalstretching sufficient to permanently elongate the non-elasticcomponents. The composite stretch laminate is then allowed to return toits substantially untensioned condition. Thus, the elastic laminate isformed into a “zero strain” stretch laminate. Herein, “zero strain”stretch laminate refers to a laminate comprised of at least two plies ofmaterial which are secured to one another along at least a portion oftheir coextensive surfaces while in a substantially untensioned (“zerostrain”) condition; one of the plies comprising a material which isstretchable and elastomeric (i.e., will return substantially to itsuntensioned dimensions after an applied tensile force has been released)and a second ply which is elongatable (but not necessarily elastomeric)so that upon stretching the second ply will be, at least to a degree,permanently elongated so that upon release of the applied tensileforces, it will not fully return to its original undeformedconfiguration. The resulting stretch laminate is thereby renderedelastically extensible, at least up to the point of initial stretching,in the direction of initial stretching.

As is noted in the above, the manufacturing process of such “zerostrain” stretch laminate includes the step of subjecting the non-elasticcomposite stretch laminate to mechanical stretching sufficient topermanently elongate the non-elastic components. This step is additionalto normal elastic lamination processes and gives limitations tomaterials to be used in the elastic laminate. For example, theelastomeric material and other composite material(s) used in the elasticlaminate need to have enough physical strength or toughness since thosematerials tend to be mechanically damaged by the process. If theelastomeric material, for example, does not have enough strength ortoughness, the elastomeric material tends to be easily shred or tom bythe stress which is applied to the elastomeric material during themechanical stretching in the manufacturing process and during the use ofproducts.

Based on the foregoing, there is a need for an elastic laminate thatdoes not have such limitations to the elastomeric material to be usedtherein.

Infants and other incontinent individuals wear disposable garments suchas diapers to receive and contain urine and other body exudates. Onetype of the disposable garments, which is often called as “tape type”,has a fastener system to hold the disposable garment at the wearer'swaist area. As the fastener system, either an adhesive tape system or amechanical fastener system is often used. Recently, elasticallystretchable ear panels tend to be preferably used in this type ofdisposable garment, because they can provide a better fit to thewearer's waist area by jointly working with the fastener system. Anothertype of disposable garments, which is often called as “pant type” or“pull-on”, has fixed sides and has become popular for use on childrenable to walk and often who are toilet training. This type of pull-ongarments has ear panels the edges of which are seamed together to formtwo leg openings and a waist opening. They also has a stretchablewaistband disposed along at least one of the end edges of the disposablegarments. These pull-on garments need to fit snugly about the waist andlegs of the wearer without drooping, sagging or sliding down fromposition on the torso to contain body exudates. Examples of thesepull-on garments are disclosed, for example, in U.S. Pat. No. 5,171,239to Igaue et al., U.S. Pat. No. 4,610,681 to Strohbeen et al., WO93/17648 published on Sep. 16, 1993, U.S. Pat. No. 4,940,464 to VanGompel et al., U.S. Pat. No. 5,246,433 to Hasse et al., and U.S. Pat.No. 5,569,234 to Buell et al.

Good performance characteristics of such stretchable ear panels andwaistband are important for these types of disposable garments. Morespecifically, the extension properties including the extension forces,recovery forces, retention forces, and available stretch (extension) ofthe ear panels and waistband are important considerations in theperformance of the fitness for pull-on garments. The extensionproperties provide the applicator and the wearer with the overallperceived “stretchiness” during use. They also effect the ability of theapplicator to achieve a suitable degree of application stretch (i.e.,for a “normally” perceived tensioning of the diaper during application,the total amount of resultant stretch is that desired toachieve/maintain good conformity of fit).

To provide good performance characteristics in stretchable ear panelsand waistband of disposable garments, elastic laminates which include anelastic material which has suitable properties have been studied andapplied to disposable garments. For example, a PCT application No.PCT/US98/05895 entitled “Elastic Member And Disposable Garment HavingImproved Fitness To Body During Entire Use” filed on Mar. 26, 1998,discloses such elastic materials for disposable garments. It isgenerally expected that disposable garments provide good fit to the bodyand/or skin of the user by using suitable elastic laminates during theentire use period of products. Typical examples of such elasticlaminates that have been previously used include composites formed froman elastic material joined to a non(or less)-elastic material such asnonwoven fabrics and plastic films. These non(or less)-elastic materialstend to affect expected elastic properties of elastic laminates. Forexample, those materials tend to decrease elastic “stretchiness” of thestretchable ear panels during use.

Based on the foregoing, there is also a need for disposable garmentswhich employ an elastic laminate that does not decrease elastic“stretchiness” thereof.

SUMMARY

The present invention is directed to an elastic laminate which iselastically extensible in at least one direction. The elastic laminateincludes an elastomeric material having a first surface and a secondsurface opposing the first surface; and a first nonwoven layer joined tothe first surface of the elastomeric material. The first nonwoven layeris formed from component fibers having a primary fiber direction. Thefirst nonwoven layer has a Fiber Orientation Ratio within about ±20degrees from the primary fiber direction of at least about 65%.

The present invention is also directed to a disposable garment having afront region, a back region and a crotch region between the front regionand the back region. The disposable garment comprises a chassis providedin the front, back and crotch regions and having edge lines in the frontand back regions. The chassis includes a liquid pervious topsheet, aliquid impervious backsheet associated with the topsheet, and anabsorbent core disposed between the topsheet and the backsheet.

In one aspect of the present invention, the disposable garment furthercomprises at least one pair of extensible side panels extendinglaterally outward from the chassis in the front or back region. At leastone of the side panels includes an elastic laminate elasticallyextensible at least in the lateral direction. The elastic laminateincludes an elastomeric material having a first surface and a secondsurface opposing the first surface; and a first nonwoven layer joined tothe first surface of the elastomeric material. The first nonwoven layeris formed from component fibers having a primary fiber direction. Thefirst nonwoven layer has a Fiber Orientation Ratio within about ±20degrees from a primary fiber direction of at least about 65%.

In another aspect of the present invention, the disposable garmentfurther comprises a waistband disposed along at least one of the endedges of the disposable garment. The waistband includes an elasticlaminate elastically extensible at least in the lateral direction. Theelastic laminate includes an elastomeric material having a first surfaceand a second surface opposing the first surface; and a first nonwovenlayer joined to the first surface of the elastomeric material. The firstnonwoven layer is formed from component fibers having a primary fiberdirection. The first nonwoven layer has a Fiber Orientation Ratio withinabout ±20 degrees from a primary fiber direction of at least about 65%.

These and other features, aspects, and advantages of the presentinvention will become evident to those skilled in the art from readingof the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the invention, it is believed that the inventionwill be better understood from the following description of preferredembodiments which is taken in conjunction with the accompanying drawingsand which like designations are used to designate substantiallyidentical elements, and in which:

FIG. 1 is a fragmentary enlarged perspective view of an elastic laminateof one preferred embodiment of the present invention, prior to beingformed into the elastic laminate;

FIG. 2 is a simplified cross-sectional view of an elastic laminate ofanother preferred embodiment;

FIG. 3 is a enlarged perspective view of an elastic laminate of yetanother embodiment of the present invention, wherein a portion of thenonwoven layer has been removed to show the bonded structure;

FIG. 4 is a fragmentary enlarged perspective view of an alternativeembodiment of the elastomeric material;

FIG. 5 is a schematic representation of a lamination device for formingthe elastic laminate shown in FIG. 3;

FIG. 6 is a perspective view of one preferred embodiment of thedisposable pull-on garment of the present invention in a typical in useconfiguration;

FIG. 7 is a perspective view of another preferred embodiment of thedisposable pull-on garment of the present invention in a typical in useconfiguration;

FIG. 8 is a simplified plan view of the embodiment shown in FIG. 7 inits flat uncontracted condition showing the various panels or zones ofthe garment;

FIG. 9 is a cross-sectional view of a preferred embodiment taken alongthe section line 9—9 of FIG. 8;

FIG. 10 is a cross-sectional view of a waistband 50 of a preferredembodiment taken along the section line 10—10 of FIG. 8;

FIG. 11 is a cross-sectional view of a waistband 50 of another preferredembodiment; and

FIG. 12 is a graph showing the two-cycles of hysteresis curves of anelastomeric material, in a preferred embodiment.

DETAILED DESCRIPTION

All cited references are incorporated herein by reference in theirentireties. Citation of any reference is not an admission regarding anydetermination as to its availability as prior art to the claimedinvention.

Herein, “comprise”, “include” and “have” mean that other element(s) andstep(s) which do not affect the end result can be added. These termsencompass the terms “consisting of” and “consisting essentially of”.

Herein, “gf” stands for gram force.

Herein, “joined” or “joining” encompasses configurations whereby anelement is directly secured to another by affixing the element directlyto the other element, and configurations whereby the element isindirectly secured to the other element by affixing the element tointermediate member(s) which in turn are affixed to the other element.

Herein, “layer” does not necessarily limit the element to a singlestratum of material in that a layer may actually comprise laminates orcombinations of sheets or webs of materials.

Herein, “nonwoven” may include any material which has been formedwithout the use of textile weaving processes which produce a structureof individual fibers which are interwoven in an identifiable manner.Methods of making suitable nonwovens includes a spunbonded nonwovenprocess, a meltblown nonwoven process, a carded nonwoven process, or thelike.

A. Laminate Structure

The present invention relates to an elastic laminate which does not havea limitation(s) to an elastomeric material to be used therein. This andother advantages of the invention are described in more detail herein.

FIG. 1 is a fragmentary enlarged perspective view of an elastic laminate70 of one preferred embodiment, prior to being formed into the elasticlaminate. (Preferred embodiments of the elastic laminate 70 after theformation are shown in FIGS. 2 and 3.) Referring to FIG. 1, the elasticlaminate 70 of the present invention includes an elastomeric layer 124having a first surface 150 and a second surface 152 opposing the firstsurface 150; and a first nonwoven layer 122 which is joined to the firstsurface 150 of the elastomeric layer 124. In a preferred embodiment, thefirst surface 150 and second surface 152 of the elastomeric layer 124are substantially parallel with the plane of the first nonwoven layer122. The first nonwoven layer 122 has an inner surface (or a firstsurface) 142 and an outer surface (or a second surface) 144. The innersurface 142 of the first nonwoven layer 122 is the surface that ispositioned facing the elastomeric layer 124.

In a preferred embodiment, the elastic laminate 70 further comprises asecond nonwoven layer 126 joined to the second surface 152 of theelastic material 70. The second nonwoven layer 126 also has an innersurface 146 and an outer surface 148. The inner surface 146 of thesecond nonwoven layer 126 is the surface that is positioned facing theelastomeric layer 124. The second surface 152 of the elastomeric layer124 is substantially parallel with the plane of the second nonwovenlayer 126. In a preferred embodiment, the nonwoven layer 126 is formedby an identical nonwoven material with that is employed in the firstnonwoven layer 122. Alternatively, the nonwoven layer 126 may be formedby a different material from that is employed in the first nonwovenlayer 122.

The elastic laminate 70 of the present invention is elasticallyextensible in at least one direction (first direction). For example, theelastic laminate 70 shown in FIG. 1 is elastically extensible in thestructural direction D. Herein, “structural direction” (e.g., D and B)is intended to mean a direction which extends substantially along andparallel to the plane of the first nonwoven layer 122. In a preferredembodiment, the elastic laminate 70 is also elastically extensible inthe second direction which is perpendicular to the first direction. Forexample, the elastic laminate 70 shown in FIG. 1 is also elasticallyextensible in the structural direction B.

B. Nonwoven Layers

The first nonwoven layer 122 of the present invention is formed fromcomponent fibers which are joined together. The component fibers have aprimary fiber direction. The first nonwoven layer 122 has a FiberOrientation Ratio within about +20 degrees from the primary fiberdirection (FOR20) of at least about 65%; more oreferably at least about75%; more preferably still at least about 85%. In a more preferredembodiment, the first nonwoven layer 122 additionally has a FiberOrientation Ratio within about ±10 degrees from the primary fiberdirection (FOR10) of at least about 45%; more preferably at least about60%; more preferably still at least about 70%.

“FOR#” (e.g., FOR10) indicates the ratio of the number of the componentfibers whose directions are within about ±# degrees, (e.g., ±10 degrees)from the primary fiber direction to the total number of componentfibers. Herein, “primary fiber direction” refers to an average directionof component fibers in the nonwoven layer. One preferred method formeasuring the Fiber Orientation Ratio of nonwoven layers is explained inmore detail below.

In a preferred embodiment, the first nonwoven layer 122 has a TensileStrength Ratio (TSR) of at least about 15, more preferably at leastabout 60. The TSR is defined by the following calculation:TSR=TS1/TS2  (1)

-   -   wherein,    -   TS1 (gf/inch): a tensile strength (TS) at the breaking point in        the primary fiber direction; and    -   TS2 (gf/inch): a tensile strength (TS) at the breaking point in        the perpendicular direction which is perpendicular to the        primary fiber direction.

Tensile Strength (ST) is measured as the maximum tensile strength valuerecorded while the first nonwoven layer 122 is stretched at a rate ofabout 20 inches/min (about 50 cm/min) to its breaking point. The tensilestrength of the first nonwoven layer 122 is measured before the firstnonwoven layer 122 is joined to the elastomeric layer 124.

In a preferred embodiment, the first nonwoven layer 122 has a tensilestrength of less than about 200 gf/inch (about 80 gf/cm) at 30%elongation to the direction which is perpendicular to the primary fiberdirection; more preferably less than about 100 gf/inch (about 40 gf/cm),more preferably still less than about 50 gf/inch (about 20 gf/cm).

The first nonwoven layer 122 may be manufactured from a wide range ofcomponent fibers including, e.g., natural fibers (e.g., wool and cottonfibers), synthetic fibers (e.g., polyolefin, polyester, nylon, and rayonfibers), or a mixture of natural fibers and/or synthetic fibers. Forease of manufacture and cost efficiency, the first nonwoven layer 122 ispreferably formed from synthetic continuous fibers. More preferably,such synthetic continuous fibers are formed from a polyolefin (e.g.,polyethylene and polypropylene) or a polyester. Preferred polyestermaterial includes a polyethylene terephthalate, a polybutyleneterephthalate and a polypropylene terephthalate, or mixtures thereof. Ina preferred embodiment, the first nonwoven layer 122 additionallyincludes component fibers formed from the other materials (i.e.,non-polyester materials) such as polyolefin and nylon.

In a preferred embodiment, the individual component fibers are formedfrom a single type of material which is selected from the abovematerials (i.e. the individual fiber is not made from polyolefin andnylon). Preferably, the component fibers are formed from a polyester,more preferably a polyethylene terepthalate, or one of its relativeswhich has an average molecular weight from about 5,000 to about 60,000,preferably from about 10,000 to about 40,000, more preferably from about14,000 to about 23,000. Alternatively, the component fibers may beformed from a mixture of two (or more) materials which are selected fromthe above materials.

In one embodiment, the component fiber has a bi-component fiberstructure formed from two distinct materials of a polyester and apolyolefin. In an alternative embodiment, the component fiber has abi-component fiber structure formed from two distinct molecular weightmaterials of one identical material, for example, a polyester. Preferredbi-component fiber structures may include a side-by-side bi-componentfiber structure and a sheath-core bi-component fiber structure known inthe art. In one embodiment, the component fiber has a bi-component fiberstructure having a core of polyolefin and a sheath of a polyester.

In a preferred embodiment, the first nonwoven layer 122 has a basisweight of less than about 60 g/m², and comprises fibers having a fiberdiameter of less than about 50 μm. More preferably, for products such asdisposable garment and the like, the first nonwoven layer 122 has abasis weight of from about 3 g/m² to about 50 g/m², more preferably fromabout 10 g/m² to about 25 g/m², and a fiber diameter of from about 1 μmto about 30 μm, more preferably from about 3 μm to about 20 μm.

The component fibers may be joined together by adhesives, thermalbonding, water-jetting, needling/felting, or other methods known in theart to form nonwoven fabrics. In a preferred embodiment, the firstnonwoven layer 122 is formed from a nonwoven manufacturing processhandling continuous component fibers or filaments known in the art.Preferred manufacturing process are described in, for example, EP0843036A1 (Kurihara et al.) published on May 20, 1998; U.S. Pat. No.5,312,500, entitled “Non-Woven Fabric and Method and Apparatus forMaking The Same”, issued to Kurihara et al. on May 17, 1994; JapaneseLaid-Open Patent Publication (Kokai) No. H2-269859 published on

Nov. 5, 1990; and Japanese Patent Publication (Kokoku) No. S60-25541published on Jun. 19, 1985.

Preferred nonwoven fabrics which are suitably applicable to the firstnonwoven layer 122 are available from Nippon Petrochemicals Co., Ltd.,Tokyo, Japan, under Code Nos. MBE8202-3-2; MBE8202-3-1; MBE7711-2;MBE6515-10; and MBE7922-1 which have the following properties.

TABLE Basis Weight FOR10 FOR20 TSR at TS at 30% Code No. (g/m²) (%) (%)Break Point elongation MBE8202-3-2 15 77 93 106 10 MBE8202-3-1 20 82 9468 20 MBE7711-2 21 69 92 76 133 MBE6515-10 8 60 85 104 21 MBE7922-1 2958 80 33 157C. Elastomeric Material

The elastomeric layer 124 may be formed in a wide variety of sizes,forms and shapes. In a preferred embodiment, the elastomeric layer 124is in the form of a continuous plane layer such as shown in, forexample, FIG. 1. Preferred forms of a continuous plane layer include ascrim, a perforated (or apertures formed) film, an elastomeric woven ornonwoven, and the like. Preferably, the elastomeric layer 124 has athickness of from about 0.05 mm to about 1 mm (about 0.002 inch-about0.039 inch). The continuous plane layer may take any shape which can besuitably provided in products. Preferred shapes of a continuous planelayer include a quadrilateral including a rectangle and a square, atrapezoid, and the other polygons. In an alternative embodiment, theelastomeric layer 124 is in the form of discrete strands (or strings)which are not connected each other.

The elastomeric material of the present invention may include allsuitable elastic materials known in the art. Elastomeric materialssuitable for use herein include synthetic or natural rubber materialsknown in the art. Preferred elastomeric materials include the diblockand triblock copolymers based on polystyrene and unsaturated or fullyhydrogenerated rubber bolcks, and their blends with other polymers suchas polyolefin polymers.

In a preferred embodiment, the elastomeric material is made from apolystyrene thermoplastic elastomer including styrene block copolymerbased materials. A preferred styrenic block copolymer based materialcontains from about 1 wt % to about 70 wt % of polystyrene, morepreferably from about 10 wt % to about 50 wt % of polystyrene.

Preferably, the polystyrene thermoplastic elastomer is selected from thegroup consisting of a styrene-butadiene-styrene thermoplastic elastomer,a styrene-isopren-styrene thermoplastic elastomer, astyrene-ethylene/butylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene thermoplastic elastomer, a hydrogenatedstyrene butadiene rubber, and a mixture thereof.

A preferred styrenic block copolymer based material contains from about1 wt % to about 70 wt % of polystyrene, more preferably from about 10 wt% to about 50 wt % of polystyrene.

In an alternative preferred embodiment, the elastomeric material 124 isa porous, macroscopically-expanded, three-dimensional elastomeric web172 as shown in FIG. 4. The web 172 has a continuous first surface 174and a discontinuous second surface 176 opposing to the first surface174. The elastomeric web 172 preferably comprises a formed filminterconnecting member 186 including at least two polymeric layers 178and 182. The first layer 178 is substantially elastic and the secondlayer 182 is substantially less elastic than the first layer 178. Atleast one of the two polymeric layers 178 and 182 is formed from apolystyrene thermoplastic elastomer. The elastomeric web 172 exhibits amultiplicity of primary apertures 184 in the first surface 174 of theweb 172. The primary apertures 184 are defined in the plane of the firstsurface 174 by a continuous network of the interconnecting member 186.The interconnecting member 186 exhibits an upwardly concave-shapedcross-section along its length. The interconnecting member 186 alsoforms secondary apertures 188 in the plane of the second surface 176 ofthe web 172. The apertures 184 and 188 may take any shape. A preferredelastomeric web is disclosed in U.S. patent application Ser. No.08/816,106, filed on Mar. 14, 1997. A preferred porous elastomericmaterial for the elastomeric layer 124 is available from Tredegar FilmProducts under the designation X-25007.

In one preferred embodiment, the elastomeric layer 124 is in the form ofa scrim 130 as shown in FIG. 1. The elastomeric scrim 130 comprises aplurality of first strands 125 which intersect or cross (with or withoutbonding to) a plurality of second strands 127 at nodes 128 at apredetermined angle α, thereby forming a net-like open structure havinga plurality of apertures 132. Each aperture 132 is defined by at leasttwo adjacent first strands 125 and at least two adjacent second strands127 such that apertures 132 are substantially rectangular (preferablysquare) in shape. Other aperture configurations, such as parallelogramsor circular arc segments, can also be provided. Such configurationscould be useful for providing non-linear elastic structural directions.Preferably, the first strands 125 are substantially straight andsubstantially parallel to one another; and, more preferably, the secondstrands 127 are also substantially straight and substantially parallelto one another. More preferably, first strands 125 intersect secondstrands 127 at nodes 128 at a predetermined angle a of about 90 degrees.Each node 128 is an overlaid node, wherein first strands 125 and secondstrands 127 are preferably joined or bonded (although it is contemplatedthat joining or bonding may not be required) at the point ofintersection with the strands still individually distinguishable at thenodes 128. However, it is believed that other node configurations suchas merged or a combination of merged and overlaid would be equallysuitable.

Although it is preferred that first and second strands 125 and 127 besubstantially straight, parallel, and intersect at an angle a of about90 degrees, it is noted that first and second strands 125 and 127 canintersect at other angles α, and that first strands 125 and/or secondstrands 127 can be aligned in circular, elliptical or otherwisenonlinear patterns relative to one another. Although for ease ofmanufacture it is contemplated that first strands 125 and second strands127 have a substantially circular cross-sectional shape prior toincorporation into elastic laminate 70 (as shown in FIG. 1), the firstand second strands 125 and 127 can also have other cross-sectionalshapes such as elliptical, square, triangular or combinations thereof.

Preferably, the material for the first strands 125 is chosen so that thefirst strands 125 can maintain the second strands 127 in relativealignment prior to forming elastic laminate 70. It is also desirablethat the materials for the first and second strands 125 and 127 arecapable of being deformed (or initially formed) into predeterminedshapes upon application of a predetermined pressure or a pressure incombination with a heat flux prior to forming elastic laminate 70. Thesedeformed shapes (e.g., elliptical second strands, substantially flatfirst strands and the like) can provide an elastic laminate 70 which canbe comfortably worn about the body without irritation or otherdiscomfort.

In a preferred embodiment, the first and second strands 125 and 127 areformed from an identical elastomeric material. For example, the firstand second strands 125 and 127 are formed from an identical polystyrenethermoplastic elastomer which is selected from the group consisting of astyrene-butadiene-styrene thermoplastic elastomer, astyrene-isopren-styrene thermoplastic elastomer, astyrene-ethylene/butylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene thermoplastic elastomer, a hydrogenatedstyrene butadiene rubber or an unsaturated styrene butadiene rubber, anda mixture thereof. A preferred elastomeric scrim 124 which containes astyrene-butadiene-styrene thermoplastic elastomer is manufactured by theConwed Plastics Company (Minneapolis, Minn., U.S.A.) under thedesignation X02514. This material has about 12 elastic strands per inch(about 5 strands/cm) in the structural direction B (i.e., the firststrands 125) and about 7 elastic strands per inch (about 3 strands/cm)in the structural direction D (i.e., the second strands 127) beforelamination.

Alternatively, the first and second strands 125 and 127 are formed fromtwo different material. For example, one of the first and second strands125 and 127 is formed from one of the above described polystyrenethermoplastic elastomer, while the other of the first and second strands125 and 127 is formed from material(s) other than the above describedpolystyrene thermoplastic elastomer. Such other material(s) may beeither elastic or non-elastic, and selected from suitable materialsknown in the art.

D. Joining Nonwoven to Elastomeric Material

The first nonwoven layer 122 of the present invention can be joined tothe elastomeric layer 124 by any means known in the art. In a preferredembodiment, the first nonwoven layer 122 is joined to the first surface150 of the elastomeric layer 124 by an adhesive means such as those wellknown in the art. For example, the first nonwoven layer 122 may besecured to the first surface 150 of the elastomeric layer 124 by auniform continuous layer of adhesive, a patterned layer of adhesive, oran array of separate lines or spots of adhesive. One preferred laminatestructure formed by an adhesive means is shown in FIG. 2.

FIG. 2 shows a simplified fragmentary enlarged side view looking intothe structural direction B of the elastic laminate 70. In thisembodiment, the elastic laminate 70 includes the second nonwoven layer126. Referring to FIG. 2, a first adhesive 170 is applied to the innersurface 142 of the first nonwoven layer 122 in positions that correspondto each of the outer edges 180 of the laminate structure 120. The firstadhesive 170 may alternatively or additionally be applied to the innersurface 146 of the second nonwoven layer 126. For ease of illustration,the description and Figs. refer to application to the first nonwovenlayer 122 only.

This pattern creates side anchor zones A, which substantially eliminatethe delamination and creep associated with previously known laminatesand which allows the elastic laminate 70 to experience higher strainswithout creeping or delaminating. It has also been found that confiningthe first adhesive 170 to the edge areas 180 of the laminate structure120 avoids impeding the extensibility of the elastic laminate 70 andalso avoids tears in the nonwoven layers 122 and 126. Preferably, thefirst adhesive 170 is applied as a plurality of beads 168, as shown inFIG. 2. Preferably, the first adhesive 170 is a flexible adhesive withan amorphous and crystallizing component. Such a preferred adhesive ismade by Ato Findley Inc., WI, U.S.A., under the designation H9224.

The side anchoring is preferably performed by side gluing with adhesivebeads to anchor the elastomeric layer 124 between the nonwoven layers122 and 126 as a part of the lamination process. Alternatively, sideanchoring may be performed by sewing, heat sealing, ultrasonic bonding,needle punching, alternative gluing processes, or by any other meansknown to those skilled in the art.

More preferably, the elastic laminate 70 includes a second adhesive 164.Preferably, the second adhesive 164 is an elastomeric adhesive. Thesecond adhesive 164 is preferably applied to the first surface 150 ofthe elastomeric layer 130. The second adhesive 164 is preferably appliedin a spiral spray pattern 166, thereby forming bond points 167 b thatare more discrete than would be formed by a linear spray application.Without being bound by theory, it is believed that most of the secondadhesive 164 is sprayed in the structural direction D (FIG. 1).Preferably, the layer of second adhesive 164 is directly applied ontothe first surface 150 of the elastomeric layer 124 in the laminationprocess.

A third adhesive 160 may also preferably be applied to the inner surface146 of the second nonwoven layer 126. Preferably, the third adhesive 160is an elastomeric adhesive. In a manner similar to that described withreference to the second spiral adhesive application 166, the thirdadhesive 160 is preferably applied in a spiral spray pattern 162,thereby forming bond points 167 a that are more discrete than would beformed by a linear spray application. Preferably, the layer of thirdadhesive 160 is directly applied onto the second surface 152 of theelastomeric layer 124 in the lamination process.

Preferably, second and third adhesives 160 and 164 are the sameelastomeric adhesive. A preferred adhesive for use in the second andthird adhesive spiral sprays 162 and 166 is made by Ato Findley Inc.,WI, U.S.A., under the designation H2120. Preferably, the add-on levelfor each of the second and third spiral sprays 162 and 166 is about 4mg/inch (about 1.6 mg/cm) to about 12 mg/inch (about 4.8 mg/cm), morepreferably about 8 mg/inch (about 3.2 mg/cm).

In an alternative preferred embodiment, the first nonwoven layer 122 isbonded to the first surface 150 of the elastomeric layer 124 by forminga heat/pressure bond between the first nonwoven layer 122 and theelastomeric layer 124. Herein, “heat/pressure bond” is either a physicalor chemical bond formed by an application of appropriate heat andpressure to two different members so that the two members can have aportion which has an increased peel strength by the formation of thebond. Herein, “peel strength” refers to the amount of force required toseparate the two members from each other. Higher peel strengthstypically equate to less chance of de-lamination of the elasticlaminates in use of products. To form such heat/pressure bond(s) betweenthe first nonwoven layer 122 and the elastomeric layer 124, any pressurecan be applied to the first nonwoven layer 122 and the elastomeric layer124 at a certain temperature as long as it does not substantially damagethe physical and/or chemical properties of the resulting elasticlaminate.

FIG. 3 is a partial perspective view of an elastic laminate 70 of yetanother embodiment, wherein a portion of the first nonwoven layer 122has been removed to show the heat/pressure bond structure. In FIG. 3,the elastomeric scrim 130 which is formed by the first and secondstrands 125 and 127 is used as an example for the elastomeric layer 124.Referring to FIG. 3, the first nonwoven layer 122 is bonded to the firstsurface 150 of the elastomeric layer 124 by forming a heat/pressure bondbetween the first nonwoven layer 122 and the elastomeric layer 124. In apreferred embodiment, the elastic laminate further includes a secondnonwoven layer (not shown in FIG. 3) which is bonded to the secondsurface 152 of the elastomeric layer 124 by forming anotherheat/pressure bond therebetween.

The heat/pressure bond is formed by softening only the material of theelastomeric layer 124 (i.e., without melting the component fibers of thefirst nonwoven layer 122). This heat/pressure bond is preferably formedby application of a bonding temperature which is lower than the meltingpoint of the material of the first nonwoven layer 122. This generallyresults in a decrease in the viscosity of the material which may or maynot involve a “melting” of the material. As a result, the componentmaterials of the elastomeric layer 124 are softened to form theheat/pressure bond. In a more preferred embodiment wherein theelastomeric layer 124 is formed from a polystyrene thermoplasticelastomer including a polystyrene segment, a bonding temperature whichis higher than the glass transition temperature of the polystyrenesegment is applied for forming the heat/pressure bond.

FIG. 5 shows one preferred example of a lamination device for formingthe elastic laminate 70 shown in FIG. 3. Referring to FIG. 5, thelamination device 800 includes a first pressure plate 801 having a firstsurface 803, and a second plate 802 having a second surface 804. Thesecond pressure plate 802 is fixed, while the first pressure plate 801is movable to apply a pressure P to the first nonwoven layer 122 and theelastomeric layer 124 in cooperation with the second pressure plate 802.Preferably, the first and second surfaces 803 and 804 are substantiallyplane and are substantially parallel each other. The first nonwovenlayer 122 is juxtaposed with the elastomeric layer 124 such that thefirst nonwoven layer 122 is immediately adjacent the elastomeric layer124. The juxtaposed two layers 122 and 124 are manually supplied to thelamination device 800. A preferred lamination device 800 is availablefrom Toyo Tester Industry Co., Ltd., Osaka, Japan, under a trade name“Heat Sealer”.

In the lamination process, the first surface 803 is heated to atemperature T1, while the second surface 804 is heated to a temperatureT2. Preferably, the temperature T1 is from about 80° C. to about 160°C., more preferably from about 100° C. to about 130° C. The temperatureT2 is preferably from about 30° C. to about 60° C., more preferably fromabout 45° C. to about 55° C. The pressure P is preferably from about 6kg/cm² to about 15 kg/cm², more preferably from about 9 kg/cm² to about11 kg/cm². The time period of the application of the pressure P ispreferably from about 1 second to about 20 seconds, more preferably fromabout 5 seconds to about 15 seconds. Preferably, the application ofpressure P can be performed two (or more) times to increase the peelstrength of the resulting laminate 70. By the application of thetemperatures T1 and T2 at the pressure P, the elastomeric layer 124 isbonded to the first nonwoven layer 122 through a heat/pressure bondwhich is formed by softening the material of the elastomeric layer 124(e.g., the polystyrene thermoplastic elastomer).

The elastic laminate 70 of the present invention can be incorporatedinto a variety of products wherein it is desired to provide an elasticstretchability in at least one structural direction either partially orentirely. Examples of such products include disposable products,including sweat bands, bandages, body wraps, and disposable garmentsincluding disposable diapers and incontinence products.

E. Test Methods

1. Test Method for Fiber Orientation

The following method is preferably used to determine the FiberOrientation Ratio (FOR) of nonwoven material.

A sample nonwoven fabric (or layer) is placed on a specimen stub. Thesample nonwoven fabric is fixed on the specimen stub at a flat conditionso that the primary fiber direction (to be defined hereinafter) of thesample nonwoven fabric can be roughly aligned with the longitudinaldirection of the photograph to be taken. A scanning electron microscope(SEM) is used to take a photograph at 50X magnification. A preferred SEMis available from Japan Electron Optics Laboratory (JEOL) Ltd., Tokyo,Japan, under Code No. JSM-5310.

The following analysis is conducted on the photograph by using adigitizer. A preferred digitizer is available from Graphtec Co., Ltd.,Tokyo, Japan, under Code No. KD9600. A photograph is placed on thedigitizer. A square area (500 μm×500 μm) is chosen at will in thephotograph on the digitizer. The both ends of every component fiberwhich can be seen in the square area are manually identified by anoperator and the coordinates thereof are detected and recorded by thedigitizer. This work is conducted on three different square areas (eachhaving 500 μm×500 μm) which are chosen at will in the photograph toobtain coordinate data on the all fibers in the three different squareareas. The orientation angle of each fiber is calculated based on thecoordinate data. The primary fiber direction of the sample nonwovenfabric is determined by the average orientation angle, which is anaverage value of the all orientation angle data obtained from the threedifferent square areas.

The Fiber Orientation Ratio within about ±10 degrees (FOR10) isdetermined by the following calculation:FOR10=NF10/TNF×100  (2)

-   -   wherein,

NF10:the number of fibers which have orientation angles within about ±10degrees from the primary fiber direction; and

TNF:the total number of fibers measured within the three differentsquare areas.

Similarly, the Fiber Orientation Ratio within about ±20 degrees (FOR20)is determined by the following calculation:FOR20=NF20/TNF×100  (3)

-   -   wherein,

NF20: the number of fibers which have orientation angles within about+20 degrees from the primary fiber direction.

2. Test Method for Tensile Strength

The following method is preferably used to measure the tensile strengthof materials.

A tensile tester is prepared. The tensile tester has an upper jaw and alower jaw which is located below the upper jaw. The upper jaw is movableand is connected to an extension force measuring means. The lower jaw isfixed in the tester. A test specimen (i.e., a nonwoven fabric to bemeasured) which has about 2.5 cm (about 1 inch) in width and about 10.2cm (about 4 inches) in length is prepared and clamped with the upper jawand the lower jaw so that the effective specimen length (L) (i.e., gaugelength) is about 5.1 cm (about 2 inch). An extension force iscontinuously applied to the test specimen through the upper jaw at across-head speed of about 50 cm (about 20 inches) per minute, until thetest specimen is physically broken. The applied extension force isrecorded by a recorder (e.g., a computer system). The tensile strengthat the breaking point is determined at the maximum tensile strengthvalue. A tensile tester suitable for use is available from InstronCorporation (100 Royall Street, Canton, MA02021, U.S.A.) as Code No.Instron 5564.

F. Disposable Garments

Herein, “pull-on garment” refers to articles of wear which have adefined waist opening and a pair of leg openings and which are pulledonto the body of the wearer by inserting the legs into the leg openingsand pulling the article up over the waist. Herein, “disposable”describes garments which are not intended to be laundered or otherwiserestored or reused as a garment (i.e., they are intended to be discardedafter a single use and, preferably, to be recycled, composted orotherwise disposed of in an environmentally compatible manner). A“unitary” pull-on garment refers to pull-on garments which are formed ofseparate parts united together to form a coordinated entity, but the earpanels are not separate elements joined to a separate chassis; rather,the ear panels are formed by at least one layer which also forms thechassis of the garment (i.e., the garment does not require separatelymanipulative panels such as a separate chassis and separate ear panels).The pull-on garment is also preferably “absorbent” to absorb and containthe various exudates discharged from the body. A preferred embodiment ofthe pull-on garment of the present invention is the unitary disposableabsorbent pull-on garment, pull-on garment 120, shown in FIG. 6. Herein,“pull-on diaper” refers to pull-on garments generally worn by infantsand other incontinent individuals to absorb and contain urine and feces.It should be understood, however, that the present invention is alsoapplicable to other pull-on garments such as training pants, incontinentbriefs, feminine hygiene garments or panties, and the like. Herein,“panel” denotes an area or element of the pull-on garment. (While apanel is typically a distinct area or element, a panel may coincide(functionally correspond) somewhat with an adjacent panel.) Herein,“uncontracted state” is used herein to describe states of pull-ongarments in its unseamed (i.e., seams are removed), flat and relaxedcondition wherein all elastic materials used are removed therefrom.

FIG. 6 shows one preferred embodiment of a disposable pull-on garment ofthe present invention (i.e., a unitary disposable pull-on diaper 120).Referring to FIG. 6, the disposable pull-on garment 120 has a frontregion 26; a back region 28 and a crotch region 30 between the frontregion 26 and the back region 28. A chassis 41 is provided in the front,back and crotch regions 26, 28 and 30. The chassis 41 includes a liquidpervious topsheet 24, a liquid impervious backsheet 22 associated withthe topsheet 24, and an absorbent core 25 (not shown in FIG. 6) disposedbetween the topsheet 24 and the backsheet 22. The chassis 41 has sideedges 220 which form edge lines 222 in the front region 26.

The pull-on garment 120 further includes at least one pair of extensibleear panels 45 each extending laterally outward from the correspondingsides of the chassis 41. Each of the ear panels 45 has an outermost edge240 which forms an outermost edge line 242. At least one of theoutermost edge lines 242 has a nonuniform lateral distance from thelongitudinal center line 100 (not shown in FIG. 6) in the uncontractedstate of the garment 120.

In a preferred embodiment, the ear panels 45 continuously extend fromthe corresponding sides of the chassis 41 in the back region 28 to thecorresponding side edges 220 of the chassis 41 in the front region 26 asshown in FIG. 6. Alternatively, the ear panels 45 may continuouslyextend from the corresponding sides of the chassis 41 in the frontregion 26 to the corresponding side edges of the chassis 41 in the backregion 28 (not shown in FIG. 6).

The pull-on garment 120 has the ear panels 45 joined to the chassis 41to form two leg openings 34 and a waist opening 36. Preferably, thepull-on garment 120 further includes seams 232 each joining the chassis41 and the ear panels 45 along the corresponding edge lines 222 and 242to form the two leg openings 34 and the waist opening 36.

FIG. 7 shows another preferred embodiment of a disposable pull-ongarment of the present invention (i.e., a unitary disposable pull-ondiaper 20). Referring to FIG. 7, the disposable pull-on garment 20includes a pair of extensible front ear panels 46 each extendinglaterally outward from the corresponding sides of the chassis 41 in thefront region 26, and a pair of extensible back ear panels 48 eachextending laterally outward from the corresponding sides of the chassis41 in the back region 28. Each of the ear panels 46 and 48 has anoutermost edge 240 which forms an outermost edge line 242. At least oneof the outermost edge lines 242 has a nonuniform lateral distance LDfrom the longitudinal center line 100 (not shown in FIG. 7 but in FIG.8) in the uncontracted state of the garment 20. The pull-on garment 20further includes seams 32 each joining the front and back ear panels 46and 48 along the corresponding edge lines 242 to form the two legopenings 34 and the waist opening 36.

In a preferred embodiment, at least one of, more preferably both of, thepairs of the ear panels 45, 46 and 48 are elastically extensible in atleast the lateral direction. In alternative embodiments, the ear panels45, 46 and 48 are elastically extensible both in the lateral andlongitudinal directions. Herein, “extensible” refers to materials thatare capable of extending in at least one direction to a certain degreewithout undue rupture. Herein, “elasticity” and “elastically extensible”refer to extensible materials that have the ability to return toapproximately their original dimensions after the force that extendedthe material is removed. Herein, any material or element described as“extensible” may also be elastically extensible unless otherwiseprovided. The extensible ear panels 45, 46 and 48 provide a morecomfortable and contouring fit by initially conformably fitting thepull-on garment to the wearer and sustaining this fit throughout thetime of wear well past when the pull-on garment has been loaded withexudates since the ear panels 45, 46 and/or 48 allow the sides of thepull-on garment to expand and contract.

The ear panels 45, 46 and 48 may be formed by unitary elements of thepull-on garment 20 or 120 (i.e., they are not separately manipulativeelements secured to the pull-on garment 20 or 120, but rather are formedfrom and are extensions of one or more of the various layers of thepull-on garment). In a preferred embodiment, each of the ear panels 45,46 and 48 is a projected member of the chassis 41 (more clearly shown inFIG. 8). Preferably, the ear panels 45, 46 and 48 include at least oneunitary element or a continuous sheet material (e.g. the nonwoven outercover 74 in FIG. 9) that forms a part of the chassis 41 and continuouslyextends into the ear panels 45, 46 and 48. Alternatively, the ear panels45, 46 and 48 may be discrete members (not shown in Figs.) which do nothave any unitary element that forms a part of the chassis 41, and may beformed by joining the discrete members to the corresponding sides of thechassis 41.

In a preferred embodiment, the pull-on garment 20 or 120 furtherincludes seam panels 66 each extending laterally outward from each ofthe ear panels 45, 46 and 48; and tear open tabs 31 each extendinglaterally outward from the seam panel 66. In a preferred embodiment,each of the seam panels 66 is an extension of the corresponding earpanels 45, 46 and 48, or at least one of the component elements usedtherein, or any other combination of the elements. More preferably, eachof the tear open tabs 31 is also an extension of the corresponding seampanel 66 or at least one of its component elements used therein, or anyother combination of its elements.

In a preferred embodiment, the corresponding edge portions of thechassis 41 and/or the ear panels 45, 46 and 48 are seamed directly orindirectly (e.g., through the seam panels 66), in an overlaping mannerto make an overlapped seam structure. Alternatively, the front and earpanels 46 and 48 can be seamed in a butt seam manner (not shown inFigs.). The bonding of the seams 32 can be performed by any suitablemeans known in the art appropriate for the specific materials employedin the chassis 41 and/or the ear panels 45, 46 and 48. Thus, sonicsealing, heat sealing, pressure bonding, adhesive or cohesive bonding,sewing, autogeneous bonding, and the like may be appropriate techniques.Preferably, the seam panels 66 are joined by a predetermined pattern ofheat/pressure or ultrasonic welds which withstands the forces andstresses generated on the garment 20 or 120 during wear.

A continuous belt 38 is formed by the ear panels 45, 46 and 48, and apart of the chassis 41 about the waist opening 36 as shown in FIGS. 6and 7. Preferably, elasticized waist bands 50 are provided in both thefront region 26 and the back region 28. The continuous belt 38 acts todynamically create fitment forces in the pull-on garment 20 or 120 whenpositioned on the wearer, to maintain the pull-on garment 20 or 120 onthe wearer even when loaded with body exudates thus keeping theabsorbent core 25 (not shown in FIG. 7) in close proximity to thewearer, and to distribute the forces dynamically generated during wearabout the waist thereby providing supplemental support for the absorbentcore 25 without binding or bunching the absorbent core 25.

FIG. 8 is a partially cut-away plan view of the pull-on garment 20 ofFIG. 7 in its uncontracted state (except in the ear panels 46 and 48which are left in their relaxed condition) with the topsheet 24 facingthe viewer, prior to the ear panels 46 and 48 being joined together bythe seams 32. The pull-on garment 20 has the front region 26, the backregion 28 opposed to the front region 26, the crotch region 30positioned between the front region 26 and the back region 28, and aperiphery which is defined by the outer perimeter or edges of thepull-on garment 20 in which the side edges are designated 150 and 240,and the end edges or waist edges are designated 152. The topsheet 24 hasthe body-facing surface of the pull-on garment 20 which is positionedadjacent to the wearer's body during use. The backsheet 22 has theouter-facing surface of the pull-on garment 20 which is positioned awayfrom the wearer's body. The pull-on garment 20 includes the chassis 41including the liquid pervious topsheet 24, the liquid imperviousbacksheet 22 associated with the topsheet 24, and the absorbent core 25positioned between the topsheet 24 and the backsheet 22. The garment 20further includes the front and back ear panels 46 and 48 extendinglaterally outward from the chassis 41, the elasticized leg cuffs 52, andthe elasticized waistbands 50. The topsheet 24 and the backsheet 22 havelength and width dimensions generally larger than those of the absorbentcore 25. The topsheet 24 and the backsheet 22 extend beyond the edges ofthe absorbent core 25 to thereby form the side edges 150 and the waistedges 152 of the garment 20. The liquid impervious backsheet 22preferably includes a liquid impervious plastic film 68.

The pull-on garment 20 also has two centerlines, a longitudinalcenterline 100 and a transverse centerline 110. Herein, “longitudinal”refers to a line, axis, or direction in the plane of the pull-on garment20 that is generally aligned with (e.g. approximately parallel with) avertical plane which bisects a standing wearer into left and righthalves when the pull-on garment 20 is worn. Herein, “transverse” and“lateral” are interchangeable and refer to a line, axis or directionwhich lies within the plane of the pull-on garment that is generallyperpendicular to the longitudinal direction (which divides the wearerinto front and back body halves). The pull-on garment 20 and componentmaterials thereof also have a body-facing surface which faces the skinof wearer in use and an outer-facing surface which is the oppositesurface to the body-facing surface.

Each of the ear panels 45, 46 and 48 has the outermost edge line 242.Herein, “edge line” refers to lines which define the outlines of the earpanels 45, 46 and 48 or the chassis 41. Herein, “outermost” refers toportions which are farthest from the longitudinal centerline 100. Atleast one of the edge lines 242 has a nonuniform lateral distance LDfrom the longitudinal center line 100 in the uncontracted state of thegarment 20.

While the topsheet 24, the backsheet 22, and the absorbent core 25 maybe assembled in a variety of well known configurations, exemplarychassis configurations are described generally in U.S. Pat. No.3,860,003 entitled “Contractible Side Portions for Disposable Diaper”which issued to Kenneth B. Buell on Jan. 14, 1975; and U.S. Pat. No.5,151,092 entitled “Absorbent Article With Dynamic Elastic Waist FeatureHaving A Predisposed Resilient Flexural Hinge” which issued to KennethB. Buell et al., on Sep. 29, 1992.

FIG. 9 is a cross-sectional view of a preferred embodiment taken alongthe section line 9—9 of FIG. 8. The pull-on garment 20 includes thechassis 41 including the liquid pervious topsheet 24, the liquidimpervious backsheet 22 associated with the topsheet 24, and theabsorbent core 25 positioned between the topsheet 24 and the backsheet22. The pull-on garment further includes the front ear panels 46 eachextending laterally outward from the chassis 41, and an inner barriercuffs 54. Although FIG. 9 depicts only the structure of the front earpanel 46 and the chassis 41 in the front region 26, preferably a similarstructure is also provided in the back region 28. In a preferredembodiment, each of the front ear panels 46 is formed by a lamination ofan extended part 72 of the barrier flap 56, an elastic laminate 70 andthe nonwoven outer cover 74. The elastic laminate 70 includes a planeelastomeric material 124 (not shown in FIG. 9 but in FIG. 11). Herein,“plane elastomeric material” refers to elastomeric materials whichcontinuously extend in two dimensional directions. Preferred planeelastomeric materials include a scrim, a perforated (or aperturesformed) film, an elastomeric woven or nonwoven, and the like. In apreferred embodiment, the plane elastomeric material 124 includes atleast a portion that has a nonuniform lateral width.

The absorbent core 25 can be any absorbent member which is generallycompressible, conformable, non-irritating to the wearer's skin, andcapable of absorbing and retaining liquids such as urine and othercertain body exudates. The absorbent core 25 may be manufactured in awide variety of sizes and shapes (e.g., rectangular, hourglass,“T”-shaped, asymmetric, etc.) and from a wide variety ofliquid-absorbent materials commonly used in disposable pull-on garmentsand other absorbent articles such as comminuted wood pulp which isgenerally referred to as airfelt. Examples of other suitable absorbentmaterials include creped cellulose wadding; meltblown polymers includingcoform; chemically stiffened, modified or cross-linked cellulosicfibers; tissue including tissue wraps and tissue laminates; absorbentfoams; absorbent sponges; superabsorbent polymers; absorbent gellingmaterials; or any equivalent material or combinations of materials.

The configuration and construction of the absorbent core 25 may vary(e.g., the absorbent core 25 may have varying caliper zones, ahydrophilic gradient, a superabsorbent gradient, or lower averagedensity and lower average basis weight acquisition zones; or may includeone or more layers or structures). Further, the size and absorbentcapacity of the absorbent core 25 may also be varied to accommodatewearers ranging from infants through adults. However, the totalabsorbent capacity of the absorbent core 25 should be compatible withthe design loading and the intended use of the garment 20.

A preferred embodiment of the garment 20 has an asymmetric, modifiedhourglass-shaped absorbent core 25 having ears in the front and backwaist regions 26 and 28. Other exemplary absorbent structures for use asthe absorbent core 25 that have achieved wide acceptance and commercialsuccess are described in U.S. Pat. No. 4,610,678 entitled “High-DensityAbsorbent Structures” issued to Weisman et al. on Sep. 9, 1986; U.S.Pat. No. 4,673,402 entitled “Absorbent Articles With Dual-Layered Cores”issued to Weisman et al. on Jun. 16, 1987; U.S. Pat. No. 4,888,231entitled “Absorbent Core Having A Dusting Layer” issued to Angstadt onDec. 19, 1989; and U.S. Pat. No. 4,834,735, entitled “High DensityAbsorbent Members Having Lower Density and Lower Basis WeightAcquisition Zones”, issued to Alemany et al. on May 30, 1989.

The chassis 41 may further include an acquisition/distribution core 84of chemically stiffened fibers positioned over the absorbent core 25,thereby forming a dual core system. In a preferred embodiment, thefibers are hydrophilic chemically stiffened cellulosic fibers. Herein,“chemically stiffened fibers” means any fibers which have been stiffenedby chemical means to increase stiffness of the fibers under both dry andaqueous conditions. Such means include the addition of chemicalstiffening agents which, for example, coat and/or impregnate the fibers.Such means also include the stiffening of the fibers by altering thechemical structure of the fibers themselves, e.g., by cross-linkingpolymer chains.

The fibers utilized in the acquisition/distribution core 84 can also bestiffened by means of chemical reaction. For example, crosslinkingagents can be applied to the fibers which, subsequent to application,are caused to chemically form intrafiber crosslink bonds. Thesecrosslink bonds can increase stiffness of the fibers. Whereas theutilization of intrafiber crosslink bonds to chemically stiffen thefibers is preferred, it is not meant to exclude other types of reactionsfor chemical stiffening of the fibers.

In the more preferred stiffened fibers, chemical processing includesintrafiber crosslinking with crosslinking agents while such fibers arein a relatively dehydrated, defibrated (i.e. individualized), twisted,curled condition. Suitable chemical stiffening agents include monomericcrosslinking agents including, but not limited to, C₂-C₈ dialdehydes andC₂-C₈ monoaldehydes having an acid functionality can be employed to formthe cosslinking solution. These compounds are capable of reacting withat least two hydroxyl groups in a single cellulose chain or onproximately located cellulose chains in a single fiber. Suchcrosslinking agents contemplated for use in preparing the stiffenedcellulose fibers include, but are not limited to, glutaraldehyde,glyoxal, formaldehyde, and glyoxylic acid. Other suitable stiffeningagents are polycarboxylates, such as citric acid. The polycarboxylicstiffening agents and a process for making stiffened fibers from themare described in U.S. Pat. No. 5,190,563, entitled “Process forPreparing Individualized, Polycarboxylic Acid crosslinked Fibers” issuedto Herron, on Mar. 2, 1993. The effect of crosslinking under theseconditions is to form fibers which are stiffened and which tend toretain their twisted, curled configuration during use in the absorbentarticles herein. Such fibers, and processes for making them are cited inthe above incorporated patents.

Preferred dual core systems are disclosed in U.S. Pat. No. 5,234,423,entitled “Absorbent Article With Elastic Waist Feature and EnhancedAbsorbency” issued to Alemany et al., on Aug. 10, 1993; and in U.S. Pat.No. 5,147,345, entitled “High Efficiency Absorbent Articles ForIncontinence Management” issued to Young, LaVon and Taylor on Sep. 15,1992. In a preferred embodiment, the acquisition/distribution core 84includes chemically treated stiffened cellulosic fiber material,available from Weyerhaeuser Co. (U.S.A.) under the trade designation of“CMC”. Preferably, the acquisition/distribution core 84 has a basisweight of from about 40 g/m² to about 400 g/m², more preferably fromabout 75 g/m² to about 300 g/m².

More preferably, the chassis 22 further includes anacquisition/distribution layer 82 between the topsheet 24 and theacquisition/distribution core 84 as shown in FIG. 9. Theacquisition/distribution layer 82 is provided to help reduce thetendency for surface wetness of the topsheet 24. Theacquisition/distribution layer 82 preferably includes carded, resinbonded hiloft nonwoven materials such as, for example, available as CodeNo. FT-6860 from Polymer Group, Inc., North America (Landisiville, NewJersey, U.S.A.), which is made of polyethylene telephthalate fibers of 6dtex, and has a basis weight of about 43 g/m². A preferable example forthe acquisition/distribution layer 82 and the acquisition/distributioncore 84 is disclosed in EP 0797968A1 (Kurt et al.) published on Oct. 1,1997.

The topsheet 24 is preferably compliant, soft feeling, andnon-irritating to the wearer's skin. Further, the topsheet 24 is liquidpervious permitting liquids (e.g., urine) to readily penetrate throughits thickness. A suitable topsheet 24 may be manufactured from a widerange of materials such as woven and nonwoven materials; polymericmaterials such as apertured formed thermoplastic films, aperturedplastic films, and hydroformed thermoplastic films; porous foams;reticulated foams; reticulated thermoplastic films; and thermoplasticscrims. Suitable woven and nonwoven materials can be included of naturalfibers (e.g., wool or cotton fibers), synthetic fibers (e.g., polymericfibers such as polyester, polypropylene, or polyethylene fibers) or froma combination of natural and synthetic fibers. The topsheet 24 ispreferably made of a hydrophobic material to isolate the wearer's skinfrom liquids which have passed through the topsheet 24 and are containedin the absorbent core 25 (i.e., to prevent rewet). If the topsheet 24 ismade of a hydrophobic material, at least the upper surface of thetopsheet 24 is treated to be hydrophilic so that liquids will transferthrough the topsheet more rapidly. This diminishes the likelihood thatbody exudates will flow off the topsheet 24 rather than being drawnthrough the topsheet 24 and being absorbed by the absorbent core 25. Thetopsheet 24 can be rendered hydrophilic by treating it with asurfactant. Suitable methods for treating the topsheet 24 with asurfactant include spraying the topsheet 24 material with the surfactantand immersing the material into the surfactant. A more detaileddiscussion of such a treatment and hydrophilicity is contained in U.S.Pat. No. 4,988,344 entitled “Absorbent Articles with Multiple LayerAbsorbent Layers” issued to Reising, et al. on Jan. 29, 1991 and U.S.Pat. No. 4,988,345 entitled “Absorbent Articles with Rapid AcquiringAbsorbent Cores” issued to Reising on Jan. 29, 1991.

In a preferred embodiment, the topsheet 24 is a nonwoven web that canprovide reduced tendency for surface wetness; and consequentlyfacilitate maintaining urine absorbed by the core 25 away from theuser's skin, after wetting. One of the preferred topsheet materials is athermobonded carded web which is available as Code No. P-8 from FiberwebNorth America, Inc. (Simpsonville, South Carolina, U.S.A.). Anotherpreferred topsheet material is available as Code No. S-2355 from HavixCo., Japan. This material is a bi-layer composite material, and made oftwo kinds of synthetic surfactant treated bicomponent fibers by usingcarding and air-through technologies. Yet another preferred topsheetmaterial is a thermobonded carded web which is available as Code No.Profleece Style 040018007 from Amoco Fabrics, Inc. (Gronau, Germany).

Another preferred topsheet 24 includes an apertured formed film.Apertured formed films are preferred for the topsheet 24 because theyare pervious to body exudates and yet non-absorbent and have a reducedtendency to allow liquids to pass back through and rewet the wearer'sskin. Thus, the surface of the formed film which is in contact with thebody remains dry, thereby reducing body soiling and creating a morecomfortable feel for the wearer. Suitable formed films are described inU.S. Pat. No. 3,929,135, entitled “Absorptive Structures Having TaperedCapillaries”, issued to Thompson on Dec. 30, 1975; U.S. Pat. No.4,324,246 entitled “Disposable Absorbent Article Having A StainResistant Topsheet”, issued to Mullane, et al. on Apr. 13, 1982; U.S.Pat. No. 4,342,314 entitled “Resilient Plastic Web Exhibiting Fiber-LikeProperties”, issued to Radel. et al. on Aug. 3, 1982; U.S. Pat. No.4,463,045 entitled “Macroscopically Expanded Three-Dimensional PlasticWeb Exhibiting Non-Glossy Visible Surface and Cloth-Like TactileImpression”, issued to Ahr et al. on Jul. 31, 1984; and U.S. Pat. No.5,006,394 “Multilayer Polymeric Film” issued to Baird on Apr. 9, 1991.

In a preferred embodiment, the backsheet 22 includes the liquidimpervious film 68 as shown in, for example, FIG. 9. Preferably, theliquid impervious film 68 longitudinally extends in the front, back andcrotch regions 26, 28 and 30. More preferably, the liquid imperviousfilm 68 does not laterally extend into the at least one of the earpanels 46 or 48. The liquid impervious film 68 has a body-facing surface79 and an outer-facing surface 77. The liquid impervious film 68 isimpervious to liquids (e.g., urine) and is preferably manufactured froma thin plastic film. However, more preferably the plastic film permitsvapors to escape from the garment 20. In a preferred embodiment, amicroporous polyethylene film is used for the liquid impervious film 68.A suitable microporous polyethylene film is manufactured by MitsuiToatsu Chemicals, Inc., Nagoya, Japan and marketed in the trade as PG-P.In a preferred embodiment, a disposable tape (not shown in Figs.) isadditionally joined to the outer surface of the backsheet 22 to providea convenient disposal after soiling.

A suitable material for the liquid impervious film 68 is a thermoplasticfilm having a thickness of from about 0.012 mm (0.5 mil) to about 0.051mm (2.0 mils), preferably including polyethylene or polypropylene.Preferably, the liquid impervious film has a basis weight of from about5 g/m² to about 35 g/m². However, it should be noted that other flexibleliquid impervious materials may be used. Herein, “flexible” refers tomaterials which are compliant and which will readily conform to thegeneral shape and contours of the wearer's body.

Preferably, the backsheet 22 further includes the nonwoven outer cover74 which is joined with the outer-facing surface of the liquidimpervious film 68 to form a laminate (i.e., the backsheet 22). Thenonwoven outer cover 74 is positioned at the outermost portion of thegarment 20 and covers at least a portion of the outermost portion of thegarment 20. In a preferred embodiment, the nonwoven outer cover 74covers almost all of the area of the outermost portion of the garment20. The nonwoven outer cover 74 may be joined to the liquid imperviousfilm 68 by any suitable attachment means known in the art. For example,the nonwoven outer cover 74 may be secured to the liquid impervious film68 by a uniform continuous layer of adhesive, a patterned layer ofadhesive, or an array of separate lines, spirals, or spots of adhesive.Suitable adhesives include a hotmelt adhesive obtainable from NittaFindley Co., Ltd., Osaka, Japan as H-2128, and a hotmelt adhesiveobtainable from H. B. Fuller Japan Co., Ltd., Osaka, Japan as JM-6064.

In a preferred embodiment, the nonwoven outer cover 74 is a cardednonwoven web, for example, obtainable from Havix Co., LTD., Gifu, Japanas E-2341. The nonwoven outer cover 74 is made of bi-component fibers ofa polyethylene (PE) and a polypropylene (PP). The ratio of PE/PP isabout 50/50. The PE/PP bi-component fiber has the dimension of 2d×51 mm.Another preferred carded nonwoven web is obtainable from Chisso Corp.,Moriyama, Japan. The nonwoven outer cover 74 is also made ofbi-component fibers of a polyethylene (PE) and a polypropylene (PP). Theratio of PE/PP is about 50/50.

In another preferred embodiment, the nonwoven web is a spunbondednonwoven web, for example, obtainable from Mitsui PetrochemicalIndustries, Ltd., Tokyo, Japan. The nonwoven web is made of bi-componentfibers of a polyethylene (PE) and a polypropylene (PP). The ratio ofPE/PP is about 80/20. The PE/PP bi-component fiber has the thickness isapproximately 2.3d. Another spunbonded nonwoven web is obtainable fromFiberweb France S. A., under Code No. 13561 DAPP.

The backsheet 22 is preferably positioned adjacent the outer-facingsurface of the absorbent core 25 and is preferably joined thereto by anysuitable attachment means known in the art. For example, the backsheet22 may be secured to the absorbent core 25 by a uniform continuous layerof adhesive, a patterned layer of adhesive, or an array of separatelines, spirals, or spots of adhesive. Adhesives which have been found tobe satisfactory are manufactured by H. B. Fuller Company of St. Paul,Minn., U.S.A., and marketed as HL-1358J. An example of a suitableattachment means including an open pattern network of filaments ofadhesive is disclosed in U.S. Pat. No. 4,573,986 entitled “DisposableWaste-Containment Garment”, which issued to Minetola et al. on Mar. 4,1986. Another suitable attachment means including several lines ofadhesive filaments swirled into a spiral pattern is illustrated by theapparatus and methods shown in U.S. Pat. No. 3,911,173 issued toSprague, Jr. on Oct. 7, 1975; U.S. Pat. No. 4,785,996 issued to Ziecker,et al. on Nov. 22, 1978; and U.S. Pat. No. 4,842,666 issued to Wereniczon Jun. 27, 1989. Alternatively, the attachment means may include heatbonds, pressure bonds, ultrasonic bonds, dynamic mechanical bonds, orany other suitable attachment means or combinations of these attachmentmeans as are known in the art.

In an alternative embodiment, the absorbent core 25 is not joined to thebacksheet 22, and/or the topsheet 24 in order to provide greaterextensibility in the front region 26 and the back region 28.

The pull-on garment 20 preferably further includes elasticized leg cuffs52 for providing improved containment of liquids and other bodyexudates. The elasticized leg cuffs 52 may include several differentembodiments for reducing the leakage of body exudates in the legregions. (The leg cuffs can be and are sometimes also referred to as legbands, side flaps, barrier cuffs, elastic cuffs or gasketing cuffs.)U.S. Pat. No. 3,860,003 entitled “Contractable Side Portions forDisposable Diaper” issued to Buell on Jan. 14, 1975, describes adisposable diaper which provides a contractible leg opening having aside flap and one or more elastic members to provide an elasticized legcuff. U.S. Pat. No. 4,909,803 entitled “Disposable Absorbent ArticleHaving Elasticized Flaps” issued to Aziz et al. on Mar. 20, 1990,describes a disposable diaper having “stand-up” elasticized flaps(barrier cuffs) to improve the containment of the leg regions. U.S. Pat.No. 4,695,278 entitled “Absorbent Article Having Dual Cuffs” issued toLawson on Sep. 22, 1987; and U.S. Pat. No. 4,795,454 entitled “AbsorbentArticle Having Leakage-Resistant Dual Cuffs” issued to Dragoo on Jan. 3,1989, describe disposable diapers having dual cuffs including agasketing cuff and a barrier cuff. U.S. Pat. No. 4,704,115 entitled“Disposable Waist Containment Garment” issued to Buell on Nov. 3, 1987,discloses a disposable diaper or incontinence garment havingside-edge-leakage-guard gutters configured to contain free liquidswithin the garment.

While each elasticized leg cuff 52 may be configured so as to be similarto any of the leg bands, side flaps, barrier cuffs, or elastic cuffsdescribed above, it is preferred that the elasticized leg cuff 52includes an elastic gasketing cuff 62 with one or more elastic strands64 as shown in FIG. 8, which is described in the above-referred U.S.Pat. Nos. 4,695,278 and 4,795,454. It is also preferred that eachelasticized leg cuff 52 further includes inner barrier cuffs 54 eachincluding a barrier flap 56 and a spacing means 58 which are describedin the above-referenced U.S. Pat. No. 4,909,803.

The pull-on garment 20 of the present invention further includes anelasticized waistband 50 that provides improved fit and containment. Theelasticized waistband 50 is that portion or zone of the pull-on garment20 which is intended to elastically expand and contract to dynamicallyfit the wearer's waist. The waistband 50 of the present inventionincludes an elastic laminate 70 which will be described in detailhereinafter. The waistband 50 is disposed along at least one, preferablyboth of the end edges 152 of the disposable garment 20. The elasticizedwaistband 50 preferably extends longitudinally inwardly from the endedge 152 of the pull-on garment 20 toward the waist edge 154 of theabsorbent core 25. Preferably, the pull-on garment 20 has twoelasticized waistbands 50, one positioned in the back region 28 and onepositioned in the front region 26, although other pull-on diaperembodiments can be constructed with a single elasticized waistband. Theelasticized waistband 50 may be constructed in a number of differentconfigurations including those described in U.S. Pat. No. 4,515,595entitled “Disposable Diapers with Elastically Contractible Waistbands”issued to Kievit et al. on May 7, 1985 and the above referenced U.S.Pat. No. 5,151,092 issued to Buell.

FIG. 10 is a cross-sectional view of one preferred embodiment takenalong the section line 10—10 of FIG. 8. As shown in FIG. 10, both thebacksheet 22 and the topsheet 24 extend beyond the waist edge 154 of theabsorbent core 25 to define a waist flap 156. Preferably, the juxtaposedareas of the backsheet 22 and the topsheet 24 are joined together by anadhesive (not shown in Figs.). In a preferred embodiment, the waistband50 is joined to the waist flap 156. Preferably, the waistband 50 isdisposed on and joined to the topsheet 24 as shown in FIG. 10.Alternatively, the waistband 50 can be disposed and joined between thebacksheet 22 and the topsheet 24 as shown in FIG. 11. The waistband 50can be joined to the topsheet 24 (and the backsheet 22) by an adhesivemeans (not shown in Figs.) such as those well known in the art. Forexample, the waistband 50 may be secured to the waist flap 156 by auniform continuous layer of adhesive, a patterned layer of adhesive, oran array of separate lines or spots of adhesive. A preferred adhesivefor use is available from Ato Findley Inc., WI, U.S.A., under thedesignation H2085.

In a preferred embodiment, the waistband 50 is secured to the waist flap156 in an elastically contractible condition so that in a normallyunrestrained configuration the waistband 50 effectively contract orgather the waist flap 156. The waistband 50 can be secured to the waistflap 156 in an elastically contractible condition in at least two ways.For example, the waistband 50 may be stretched and secured to the waistflap 156 while the waist flap 156 is in an uncontracted condition.Alternatively, the waist flap 156 may be contracted, for example bypleating, and the waistband 50 is secured to the contracted waist flap156 while the waistband 50 in its relaxed or unstretched condition.

Yet alternatively, the waistband 50 is joined, in its relaxed orunstretched condition, to the waist flap 156 which is in an uncontractedcondition, thereby forming a composite laminate with the materials ofthe backsheet 22 and the topsheet 24. At least a portion, preferably theentire portion of the composite laminate is then subjected to mechanicalstretching sufficient to permanently elongate the non-elastic componentswhich are the backsheet 22 and the topsheet 24. The composite laminateis then allowed to return to its substantially untensioned condition.Thus, the composite laminate is formed into a “zero strain” stretchlaminate which works as elasticized waistband 50.

Herein, “zero strain” stretch laminate refers to a laminate included ofat least two plies of material which are secured to one another along atleast a portion of their coextensive surfaces while in a substantiallyuntensioned (“zero strain”) condition; one of the plies including amaterial which is stretchable and elastomeric (i.e., will returnsubstantially to its untensioned dimensions after an applied tensileforce has been released) and a second ply which is elongatable (but notnecessarily elastomeric) so that upon stretching the second ply will be,at least to a degree, permanently elongated so that upon release of theapplied tensile forces, it will not fully return to its originalundeformed configuration. The resulting stretch laminate is therebyrendered elastically extensible, at least up to the point of initialstretching, in the direction of initial stretching. Particularlypreferred methods and apparatus used for making stretch laminatesutilize meshing corrugated rolls to mechanically stretch the components.Particularly preferred apparatus and methods are disclosed in U.S. Pat.No. 5,167,897 issued to Weber et al. on Dec. 1, 1992; U.S. Pat. No.5,156,793 issued to Buell et al. on Oct. 20, 1990; and U.S. Pat. No.5,143,679 issued to Weber et al. on Sep. 1, 1992.

In a preferred embodiment, the waistband 50 extends across essentiallythe entire lateral width of the absorbent core 25. Herein, “lateralwidth” refers to the dimension between the side edges of components ofdisposable garments. Herein, “across essentially” is used in thiscontext to indicate that the waistband 50 does not need to extendabsolutely across the entire width of the absorbent core 25 so long asit extends sufficiently far across the width thereof to provide theelasticized waistband. Preferably, the waistband 50 extends across onlya portion of the lateral width of the absorbent core 25, more preferablyat least between portions in the ear panels 46 and 48 (as shown in FIG.8). In one preferred embodiment, the waistband 50 extends across theentire lateral width of the garment 20 (not shown Figs.).

The extent to which the waistband 50 extends inboard from the end edge152 of the garment 20, and thus the longitudinal span of the resultantwaistband, can vary according to the particular construction of thegarment 20. The longitudinal span of the waistband 50 is at least about5 mm, preferably from about 6 mm to about 60 mm, more preferably fromabout 15 mm to about 30 mm.

At least one of the ear panels 45, 46 and 48 includes the elasticlaminate 70 of the present invention. For example, each of the front earpanels 46 shown in FIG. 9 includes the elastic laminate 70 whichincludes the elastomeric material 124 (not shown in FIG. 9) whichpreferably extends laterally outward from the chassis 41 to provide goodfitness by generating the optimal retention (or sustained) force at thewaist and side areas of the wearer. Preferably, the elastomeric material124 is extensible in at least one direction, preferably in the lateraldirection to generate a retention (or sustained) force that is optimalto prevent the pull-on garment 20 from drooping, sagging, or slidingdown from its position on the torso without causing the red marking onthe skin of the wearer. In a preferred embodiment, each of the earpanels 45, 46 and 48 includes the elastomeric material 124.

The elastic laminate 70 is operatively joined to at least one of thenonwoven webs 72 and 74 in the ear panels 45, 46 and 48 to allow theelastic laminate 70 to be elastically extensible in at least the lateraldirection. In a preferred embodiment, the elastic laminate 70 isoperatively joined to the nonwoven webs 72 and 74 by securing them to atleast one, preferably both of the nonwoven webs 72 and 74 while in asubstantially untensioned (zero strain) condition.

The elastic laminate 70 can be operatively joined to the nonwoven webs72 and 74, by using either an intermittent bonding configuration or asubstantially continuous bonding configuration. Herein, “intermittently”bonded laminate web means a laminate web wherein the plies are initiallybonded to one another at discrete spaced apart points or a laminate webwherein the plies are substantially unbonded to one another at discretespaced apart areas. Conversely, a “substantially continuously” bondedlaminate web means a laminate web wherein the plies are initially bondedsubstantially continuously to one another throughout the areas ofinterface. It is preferred that the stretch laminate be bonded over allor a significant portion of the stretch laminate so that the inelasticwebs (i.e., the nonwoven webs 72 and 74) elongate or draw withoutcausing rupture, and the layers of the stretch laminates are preferablybonded in a configuration that maintains all of the layers of thestretch laminate in relatively close adherence to one another after theincremental mechanical stretching operation. Consequently, the elasticpanel members and the other plies of the stretch laminate are preferablysubstantially continuously bonded together using an adhesive. In aparticularly preferred embodiment, the adhesive selected is applied witha control coat spray pattern at a basis weight of about 7.0 grams/squarem. The adhesive pattern width is about 6.0 cm. The adhesive ispreferably an adhesive such as is available from Nitta Findley Co.,Ltd., Osaka, Japan, under the designation H2085F. Alternatively, theelastic panel member and any other components of the stretch laminatesmay be intermittently or continuously bonded to one another using heatbonding, pressure bonding, ultrasonic bonding, dynamic mechanicalbonding, or any other method as is known in the art.

After the elastic laminate 70 is operatively joined to at least one ofthe nonwoven webs 72 and 74, at least a portion of the resultantcomposite stretch laminate is then subjected to mechanical stretchingsufficient to permanently elongate the non-elastic components which are,for example, the nonwoven webs 72 and 74. The composite stretch laminateis then allowed to return to its substantially untensioned condition. Atleast one pair of, preferably both of the ear panels 45, 46 and 48 isthus formed into “zero strain” stretch laminates. (Alternatively, theelastic laminate 70 could be operatively joined in a tensioned conditionand then subjected to mechanical stretching; although this is not aspreferred as a “zero strain” stretch laminate.)

The elastic laminate 70 is preferably joined to, more preferablydirectly secured to the respective edges 78 of the liquid imperviousfilm (i.e., the liquid impervious film 68) through an adhesive 76 asshown in FIG. 9. In a preferred embodiment, while liquid impervious film68 longitudinally extends in the front, back and crotch regions 26, 28and 30, it does not laterally extend into at least one of, preferablyeach of the extensible ear panels 45, 46 and 48. In a more preferredembodiment, the elastic laminate 70 is joined to the respective edges 78of the liquid impervious film 68 at the outer-facing surface 77 as shownin FIG. 9. In an alternative embodiment, the elastic laminate 70 may bejoined to the respective edges 78 of the liquid impervious film 68 atthe body-facing surface 79 (not shown in Figs.). Preferably, theadhesive 76 is applied in a spiral glue pattern. In a preferredembodiment, the adhesive 76 is a flexible adhesive with an amorphous andcrystallizing component. Such a preferred adhesive is made by NittaFindley Co., Ltd., Osaka, Japan, under the designation H2085F.Alternatively, the elastic laminate 70 may be joined to the respectiveedges 78 of the liquid impervious film 68 by any other bonding meansknown in the art which include heat bonds, pressure bonds, ultrasonicbonds, dynamic mechanical bonds, or combinations of these attachmentmeans.

It is understood that the examples and embodiments described herein arefor illustrative purpose only and that various modifications or changeswill be suggested to one skilled in the art without departing from thescope of the present invention.

1. An elastic laminate elastically extensible in at least one direction,comprising: (a) an elastomeric layer having a first surface and a secondsurface opposing the first surface; wherein the elastomeric layer is ina form selected from the group consisting of a scrim, an aperturesformed film, an elastomeric woven or nonwoven, discrete strands andstrings; wherein the elastomeric woven or nonwoven and discrete strandand strings comprise a polystyrene thermoplastic elastomer selected fromthe group consisting of a styrene-butadiene-styrene thermoplasticelastomer, a styrene-isoprene-styrene thermoplastic elastomer, astyrene-ethylene/butylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene thermoplastic elastomer, a hydrogenatedstyrene butadiene rubber, and a mixture thereof; and (b) a firstnonwoven layer joined to the first surface of the elastomeric layer, thefirst nonwoven layer being formed from component fibers having a primaryfiber direction; wherein the first nonwoven layer has a FiberOrientation Ratio within about ±20 degrees from a primary fiberdirection of at least about 65%; wherein the elastic laminate exhibitselasticity without mechanical stretching of the first nonwoven layerduring manufacture.
 2. The elastic laminate according to claim 1,wherein the first nonwoven layer has a Tensile Strength Ratio of atleast about
 15. 3. The elastic laminate of claim 1, wherein the firstnonwoven layer has a stress of less than about 200 gf/inch (about 80gf/cm) at 30% elongation.
 4. The elastic laminate of claim 1, whereinthe first nonwoven layer has a Fiber Orientation Ratio within about ±10degrees from the primary fiber direction of at least about 45%.
 5. Theelastic laminate of claim 1, wherein the first nonwoven layer has abasis weight of less than about 60 g/m².
 6. The elastic laminate ofclaim 1, further comprising a second nonwoven layer joined to the secondsurface of the elastomeric material.
 7. The elastic laminate of claim 1,wherein the first nonwoven layer is made from synthetic continuousfibers.
 8. The elastic laminate of claim 7, wherein the syntheticcontinuous fibers are made from a polyolefin or a polyester.
 9. Theelastic laminate of claim 7, wherein the synthetic continuous fibers arebicomponent fibers.
 10. A disposable garment having a front region, aback region and a crotch region between the front region and the backregion, comprising: a chassis provided in the front, back and crotchregions and having edge lines in the front and back regions, the chassiscomprising a liquid pervious topsheet, a liquid impervious backsheetassociated with the topsheet, and an absorbent core disposed between thetopsheet and the backsheet; and at east one pair of extensible sidepanels extending laterally outward from the chassis in the font or backregion, wherein at least one of the side panels including an elasticlaminate elastically extensible at least in the lateral direction, theelastic laminate including; (a) an elastomeric layer having a firstsurface and a second surface opposing the first surface; wherein theelastomeric layer is in a form selected from the group consisting of ascrim, an apertures formed film, an elastomeric woven or nonwoven,discrete strands and strings; wherein the elastomeric woven or nonwovenand discrete strand and strings comprise a polystyrene thermoplasticelastomer selected from the group consisting of astyrene-butadiene-styrene thermoplastic elastomer, astyrene-isoprene-styrene thermoplastic elastomer, astyrene-ethylene-butylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene thermoplastic elastomer, a hydrogenatedstyrene butadiene rubber, and a mixture thereof; and (b) a firstnonwoven layer joined to the first surface of the elastomeric layer, thefirst nonwoven layer being formed from component fibers having a primaryfiber direction; wherein the first nonwoven layer has a FiberOrientation Ratio within about ±20 degrees from a primary fiberdirection of at least about 65%; wherein the elastic laminate exhibitselasticity without mechanical stretching of the first nonwoven layerduring manufacture.
 11. A disposable garment having a longitudinalcenter line, longitudinal edges, end edges, a front region, a backregion and a crotch region between the front region and the back region,comprising: a chassis provided in the front, back and crotch regions andhaving edge lines in the front and back regions, the chassis comprisinga liquid pervious topsheet, a liquid impervious backsheet associatedwith the topsheet, and an absorbent core disposed between the topsheetand the backsheet; and a waistband disposed along at least one of theend edges of the disposable garment, wherein the waistband includes anelastic laminate including (a) an elastomeric layer having a firstsurface and a second surface opposing the first surface; wherein theelastomeric layer is in a form selected from the group consisting of ascrim, an apertures formed film, an elastomeric woven or nonwoven,discrete strands and strings; wherein the elastomeric woven or nonwovenand discrete strands and strings comprise a polystyrene thermoplasticelastomer selected from the group consisting of astyrene-butadiene-styrene thermoplastic elastomer, astyrene-isoprene-styrene thermoplastic elastomer, astyrene-ethylene/butylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene-styrene thermoplastic elastomer, astyrene-ethylene/propylene thermoplastic elastomer, a hydrogenatedstyrene butadiene rubber, and a mixture thereof; and (b) a firstnonwoven layer joined to the first surface of the elastomeric layer, thefirst nonwoven layer being formed from component fibers having a primaryfiber direction; wherein the first nonwoven layer has a FiberOrientation Ratio within about ±20 degrees from a primary fiberdirection of at least about 65%; wherein the elastic laminate exhibitselasticity without mechanical stretching of the first nonwoven layerduring manufacture.
 12. The disposable garment of claim 10, furthercomprising seams which join the chassis to the side panels to form twoleg openings and a waist opening.
 13. The disposable garment of claim10, wherein the at least one pair of the side panels comprises one pairof extensible front side panels extending laterally outward from thechassis in the front region, and one pair of extensible back side panelsextending laterally outward from the chassis in the back region, and thedisposable garment further comprises seams each joining the front andback side panels to form the two leg openings and the waist opening. 14.The disposable garment of claim 10, wherein the first nonwoven layer hasa Tensile Strength Ratio of at least about
 15. 15. The disposablegarment of claim 10, wherein the first nonwoven layer has a stress ofless than about 200 gf/inch (about 80 gf/cm) at 30% elongation.
 16. Thedisposable garment of claim 10, wherein the first nonwoven layer has aFiber Orientation Ratio within about ±10 degrees from the primary fiberdirection of at least about 45%.
 17. The disposable garment of claim 10,further comprising a second nonwoven layer joined to the second surfaceof the elastomeric material.
 18. The disposable garment of claim 10,wherein the elastomeric material is in the form of a continuous planelayer or a strand.
 19. The disposable garment of claim 10, wherein thefirst nonwoven layer is formed from synthetic continuous fibers whichare made from a polyolefin or a polyester.